The present invention relates to an apparatus and method for compensating a steering angle signal and motor angle signal of an MDPS (Motor-Driven Power Steering) system, and more particularly, an apparatus and method for compensating a steering angle signal and motor angle signal of an MDPS system, which synchronizes a steering angle signal and a motor angle signal.
A power steering of a vehicle is a power-based steering apparatus, and serves to assist a driver with a steering wheel operation. Such a power steering generally uses hydraulic pressure. Recently, however, the use of an MDPS system using the force of a motor has increased. That is because the MDPS system has a smaller weight and occupies a smaller area than the existing hydraulic power steering system, and does not require an oil change.
Unlike the existing hydraulic power steering system, the MDPS system generates a torque through current control of the motor by a control unit such as an ECU (Electronic Control Unit), and thus includes a variety of control logics for controlling the motor. Such control logics are divided into logic for implementing a steering feel desired by a driver, logic for improving the stability of the vehicle, and logic for improving the stability of the system. The control unit of the MDPS system controls the respective logics based on various parameters such as vehicle speed, torque signal, steering angle signal and motor angle signal.
Among the parameters, the steering angle and the motor angle are parameters required for implementing a sophisticated steering feel. For example, the steering angle can be calculated through post-processing for a signal measured by a steering angle sensor installed in a column assembly, and the motor angle can be calculated through post-processing for a signal measured through a motor angle sensor (an encoder of a motor).
In the related art, however, since the steering angle signal and the motor angle signal are not synchronized with each other, only one of the steering angle signal and the motor angle signal is used to design logic. Therefore, it is difficult to acquire desired steering logic and target performance.
The related art of the present invention is disclosed in Korean Patent Publication No. 10-2015-0065421 published on Jun. 15, 2015.